Method of integrally forming light-guide and polarizer

ABSTRACT

A method of integrally forming light-guide board and polarizer. A polarizer and a mold with a first space and a second space are provided. The polarizer is fixed in the first space. A light-guide material is injected into the second space. By curing the light-guide material, a light-guide board is formed, and the polarizer and the light-guide are integrated together.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the priority benefit of Taiwanapplication serial no. 90117786, filed Jul. 20, 2001.

BACKGROUND OF INVENTION

[0002] 1. Field of the Invention

[0003] The invention relates in general to a method for integrallyforming a light-guide board and an optical thin film built in a liquidcrystal display (LCD), and more particularly, to a method of integrallyforming a light-guide board and a polarizer.

[0004] 2. Description of the Related Art

[0005] In recent years, the liquid crystal display, accompanied with theadvancement of electronic devices, has developed widely applied andversatile functions. However, the method for forming the liquid crystaldisplay has become consequently more complicated. Generally speaking,the liquid crystal display can be categorized into three types, thereflective type liquid crystal display, the transmissive type liquidcrystal display and the transflective type liquid crystal display.

[0006]FIG. 1 shows a light-guide board and a polarizer on a glasssubstrate of a conventional liquid crystal display. The light-guideboard and the polarizer are adhered to each other with an adhesivematerial. FIG. 2 shows a cross sectional view of FIG. 1.

[0007] Referring to both FIGS. 1 and 2, in the conventional liquidcrystal display module, the front light comprises a light-guide board100 and a polarizer 102. The light-guide board 100 and the polarizer 102are provided as two separate devices. Normally, after the light-guideboard 100 and the polarizer 102 are fabricated, an adhesive material 104is used to adhere the light-guide board 100 and the polarizer 102. Thelight-guide board 100 has burnishing terminals 100 b and 100 c, and apattern surface 100 a to result in incident light thereof being emittedmore uniformly.

[0008] An additional step for adhesive material 104 is required tointegrate the light-guide board 100 and the polarizer 102 together.Therefore, not only is the labor cost increased, but also the materialcost (the adhesive material). Further, as the light-guide board 100 andthe polarizer 102 are attached manually, the automation for massproduction cannot be achieved.

SUMMARY OF INVENTION

[0009] The major objective of the present invention is to provide amethod for integrally forming a light-guide board and an optical thinfilm, and more particularly, to provide a method for integrally forminga light-guide board and a polarizer to reduce the fabrication cost of aliquid crystal display module.

[0010] Another objective of the present invention is to provide a methodfor integrally forming a light-guide board and an optical thin film, andmore particularly, to provide a method for integrally forming alight-guide board and a polarizer to increase the efficiency for forminga liquid crystal display module.

[0011] Still another objective of the present invention is to provide amethod for integrally forming the light-guide board and the optical thinfilm, and more particularly, to provide a method for integrally forminga light-guide board and a polarizerto allows for automated massproduction.

[0012] To prevent disadvantages of the prior art, the present inventionprovides a method for integrally forming the light-guide board and theoptical thin film, and more particularly, to provide a method forintegrally forming a light-guide board and a polarizer includes thefollowing steps. A polarizer and a mold are provided. The mold has afirst space and a second space. The polarizer is disposed in the firstspace of the mold. A light-guide material such as a polymer material isinjected into the second space of the mold. The method for injecting thelight-guide material includes using a lying type injection moldingmachine, a lying type compression molding machine, a lying typeinjection compression molding machine, a standing type injection moldingmachine, a standing type compression molding machine, and a standingtype injection compression molding machine. Being injected into thesecond space of the mold, the light-guide material is cured to form alight-guide board.

[0013] Therefore, the polarizer and the light-guide board are adhered toeach other at the same time. The integrated light-guide board andpolarizer can be applied to the front light of a liquid crystal display.

[0014] Thus the structure with the optical thin film and the light-guideboard are constructed integrally without an additional adhering step andmaterial. The fabrication cost is thus greatly reduced.

[0015] The integrated structure of the optical thin film and thelight-guide board can be formed by injection molding, compressionmolding or injection compression molding methods to omit the step ofadhering the optical and the light-guide board, and thus the fabricationtime is reduced.

[0016] The above method for forming the integrated structure of thepolarizer and the light-guide board uses injection molding method,compression molding method or injection compression molding method toachieve the objective of automated mass production.

[0017] Both the foregoing general description and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the invention, as claimed.

BRIEF DESCRIPTION OF DRAWINGS

[0018]FIG. 1 shows a lateral view of a light-guide board and a polarizerof a conventional liquid crystal display;

[0019]FIG. 2 shows a cross-sectional view of FIG. 1;

[0020]FIG. 3 shows a cross-sectional view of the polarizer and moldaccording to a preferred embodiment of the present invention;

[0021]FIG. 4 shows the three-dimensional drawing of the integratedstructure according to a preferred embodiment of the present invention;and

[0022]FIG. 5 shows a cross-sectional view of FIG. 4.

DETAILED DESCRIPTION

[0023]FIG. 3 shows a cross-sectional view of the polarizer and moldaccording to a preferred embodiment of the present invention.

[0024] As shown in FIG. 3, a mold 210 and a polarizer 202 are provided.It is appreciated that the polarizer 202 is used as an example only, andthe invention can also be applied to formation of other optical thinfilm, such as multi-layer thin film or single-layer thin film. The mold210 has a first space 212 and a second space 214. The polarizer 202 isdisposed into the first space 212 of the mold 210. The first space 212has a surface 212 a, on which no pattern is formed.

[0025] For example, using an injection molding method, a meltedlight-guide material is injected into the second space 214 of the mold210. Therefore, the polarizer 202 and a light-guide board 200 are formedintegrally as in FIG. 4. The molding method further includes compressionmolding and injection compression molding. The machine applied for themolding process includes a lying type molding machine or a standing typemolding machine to inject the light-guide material into the second space214 of the mold 210. While the lying type machine is used to form theintegrated structure 204 of the polarizer 202 and the light-guide board200, the polarizer 202 is fixed in the first space 212 using a vacuumsuction. If a standing type machine is used, gravitation force isdirectly applied to dispose the polarizer 202 in the first space 212 ofthe mold 210. The material of the light-guide material includes apolymer, for example. The second space 214 of the mold 210 may have arugged surface 214 a for forming a pattern surface of the light-guideboard in the post-process.

[0026]FIG. 4 shows the three-dimensional drawing of the integratedstructure according to a preferred embodiment of the present invention,and FIG. 5 shows a cross-sectional view of FIG. 4.

[0027] Referring to FIGS. 4 and 5, the melted light-guide material isinjected into the mold 210 by injection molding method, for example.Then the injected light-guide material in the second space 214 of themold 210 is cured to become a light-guide board 200. Therefore, anintegrated structure 204 including the polarizer 202 and the light-guideboard 200 is formed in an integrated structure.

[0028] In the embodiment above-mentioned, the light-guide board 200 ofthe integrated structure 204 has burnishing terminals 200 b and 200 cand a pattern surface 200 a to result in a uniform emission of a lightincident thereon. The light-guide board 200 of the integrated structure204 having the light-guide board and polarizer can be formed by thetechnology of simultaneous formation after emission, the technology offormation after compressing, the technology of simultaneous formationafter emission and compressing, and so on, to be formed on a surface ofthe polarizer 202. The integrated structure 204 with the light-guideboard 200 and the polarizer 202 can be applied as a front lightlight-guide board.

[0029] In the embodiment above-mentioned, the optical thin film, such aspolarizer, is disposed in the mold, followed by forming the light-guideboard in the mold using injection molding, compression molding orinjection compression mold and then an integrated structure is formed.The problems of the conventional method of adhering separated polarizerand light-guide board by using adhesive material are thus resolved. Thefabrication cost is thus reduced, the additional attaching step saved,and the automated mass production of liquid crystal display modules isachieved. The invention can be applied to a reflective type liquidcrystal display or other types of liquid crystal displays.

[0030] The invention includes at least the following advantages:

[0031] 1. By integrally forming the polarizer and the light-guide board,an additional adhering step for adhesive material is saved to reduce thefabrication cost.

[0032] 2. Since the integrated structure with the polarizer and thelight-guide board are formed using injection molding, compressionmolding or injection compression molding, and an additional adheringstep is omitted and the fabrication time is reduced.

[0033] 3. By using the injection molding, compression molding orinjection compression molding to form the integrated structure with thepolarizer and the light-guide board, the objective of automated massproduction can be achieved.

[0034] Other embodiments of the invention will appear to those skilledin the art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples are to be considered as exemplary only, with a true scope andspirit of the invention being indicated by the following claims.

1. A method of integrally forming an integrated structure of alight-guide board and an optical thin film, comprising: providing theoptical thin film, a mold, and a polarizer, wherein the mold has a firstspace and a second space; disposing the optical thin film in the firstspace of the mold; and injecting a light-guide material into the secondspace of the mold.
 2. The method according to claim 1, wherein the stepof providing the optical thin film includes a step of providing amulti-layer thin film.
 3. The method according to claim 1, wherein thestep of providing the optical thin film includes a step of providing asingle-layer thin film.
 4. The method according to claim 1, wherein thestep of injecting the light-guide material includes injection molding,compression molding and injection compression molding.
 5. The methodaccording to claim 4, wherein the injection molding step uses a lyingtype injection machine.
 6. The method according to claim 4, wherein theinjection molding step uses a standing type injection machine.
 7. Themethod according to claim 4, wherein the step of injecting thelight-guide material includes injecting a polymer.
 8. A method ofintegrally forming a structure of a light-guide board and an opticalthin film, comprising: providing the optical thin film, a polarizer, anda mold, wherein the mold has a first space and a second space; disposingthe optical thin film on one surface of the mold; and injecting alight-guide material in the mold to fill another space without theoptical thin film, and curing the light-guide material to form alight-guide board adhered to the optical thin film.
 9. The methodaccording to claim 8, wherein the step of providing the optical thinfilm includes a step of providing a multi-layer thin film.
 10. Themethod according to claim 8, wherein the step of providing the opticalthin film includes a step of providing a single-layer thin film.
 11. Themethod according to claim 8, wherein the step of injecting thelight-guide material includes injection molding, compression molding andinjection compression molding.
 12. The method according to claim 11,wherein the injection molding step uses a lying type injection machine.13. The method according to claim 11, wherein the injection molding stepuses a standing type injection machine.
 14. The method according toclaim 8, wherein the step of injecting the light-guide material includesinjecting a polymer.
 15. A method of integrally forming a structure witha light-guide board and an optical thin film, comprising providing apolarizer, disposing the optical thin film into a mold, and forming thelight-guide board on a surface opposing to the optical thin film via aninjection molding, a compression molding or an injection compressionmolding step.
 16. The method according to claim 15, wherein the step ofdisposing the optical thin film includes a step of disposing amulti-layer thin film.
 17. The method according to claim 15, wherein thestep of disposing the optical thin film includes a step of disposing asingle-layer thin film.
 18. The method according to claim 15, furthercomprising using a lying type injection machine for forming thelight-guide board.
 19. The method according to claim 15, furthercomprising using a standing type injection machine for forming thelight-guide board.